Patent GB-442735-A (GB)
Title: A device for automatically disengaging and engaging a free run controlling clutch ofa power driven vehicle upon closing and opening, respectively, the engine throttle
Filed: 1934-08-13
Abstract: 442,735. Operating clutches of motor vehicles. MAYBACH - MOTORENBAU GES., Friedrichshafen, Germany. Aug. 13, 1934, No. 23376. Convention date, Aug. 17, 1933. [Class 80 (ii)] [See also Group XXXI] In a motor vehicle wherein a clutch is automatically disengaged and engaged, or a free-wheel clutch is automatically unlocked and locked, upon closing and opening, respectively, the engine throttle, so as to allow coacting, and is also automatically engaged upon applying the vehicle brake, the clutch remains engaged upon release of the brake until the throttle has again been opened and closed. The supply of compressed air from a container 1 through a conduit 2 to a servomotor 5 operating the brake 7 is controlled by a valve 9 connected to the brake pedal 10, and the supply from the container 1 through a conduit 4, 19 to a servomotor 6 operating the clutch 8 is controlled by two piston valves 11, 12 in series. The valve 11 is connected to the accelerator 14 while the valve 12 is urged to the left by a spring 17 and is adapted to be moved to the right by a piston 22 adapted to be moved by compressed air supplied from the container 1 through a conduit 24 under the control of a piston valve 26 controlled by the pressure in the conduit 2. The parts are shown in normal position, with the brake pedal and accelerator released. In this position, valve 9 opens the conduit 2 to atmosphere and the conduit 24 is open to atmosphere through a vent 29, while the valves 11, 12 put the servo 6 into communication with the container 1 so that the clutch is disengaged. Upon depressing the accelerator, the valve 11 moves to open the servo 6 to atmosphere through a vent 16 and the clutch engages. If, with the accelerator released, the brake pedal 10 is depressed to apply the brake with more than a predetermined force, the valve 26 is moved up to put the conduit 24 into communication with container 1. The piston 22 thus moves to the right, carrying with it the valve 12, which puts the conduit 19 into communication with atmosphere through a vent 20 and the clutch engages. Upon releasing the pedal 10, the valve 26 and piston 22 return to normal position, but valve 12 remains in its right-hand position, since compressed air acts on its left-hand end through a passage 23. If now the accelerator is depressed, the conduit 4 is put into communication with atmosphere through vent 16, and valve 12 therefore returns to its normal position, the clutch remaining engaged. Upon now releasing the accelerator, the clutch disengages. As described in Specification 402,957, the clutch servo may be rendered operative or inoperative by the action of a manually-operable control member, and the arrangement may be such that the clutch will be re-engaged after disengagement only when the two clutch parts run in synchronism, when the control member is in either the " on " or the " off " position. In such a case, the normally-operable control member is arranged between the valves 11 and 12.